Hilde Lindemann’s baby sister, Carla, was born with hydrocephaly — a condition in which fluid around the brain impairs mental function. It was untreatable, and Carla died before she was two years old.
In Lindemann’s new book, Holding and Letting Go: The Social Practice of Personal Identity, she observes that despite Carla’s helplessness the family treated her as a full member of the family, a person. This raises a number of intriguing questions about the nature of personhood, a status usually reserved for fully functioning adults.

Personhood

Personhood is a moral concept, related to the notion of individuality. Very roughly, a person is someone who matters in his or her own right, and who therefore deserves our highest moral consideration. But what makes someone matter?
Enlightenment philosopher Immanuel Kant claimed that personhood is grounded in reason. We have an inviolable moral status insofar as we are rational creatures: ones that are capable of giving and receiving reasons when considering how to act.
I can’t lie to you, for instance, because in doing so I would be undermining your ability to reason correctly and thus would not be treating you according to your proper status. Lying to you is (most of the time) disrespectful. So is stealing from you, killing you, treating you unfairly, and so on.
Kant’s conception of a person goes a long way toward showing why humans are important and what our importance requires of us as we interact with one another. But notice that there could be non-human rational creatures, and not all humans are rational creatures.
So, in the Kantian sense some non-human things could be persons, and some humans are not persons. The former observation doesn’t usually bother people anymore; science fiction has now made us used to the idea that other creatures could have the same moral status as humans do. But the latter is problematic.
If personhood requires rationality, then what should we say about children, who are at best partially rational? What should we say about those with mental disabilities that hamper their reason? What should we say about Carla?
Surely, children and the mentally disabled are morally important, and, you might think, they matter in just the same way as everyone else. You could argue that we accord children moral importance based on their potential for rationality, but this argument does not hold water when it comes to permanent mental disability.
Another way to go is to say simply that children and the mentally disabled are not persons, or not full persons. But then how do we explain the strong sense we have that they are still important? Do we, as full persons, somehow make them important? No, they are important in their own right, as individuals.
So another approach is needed to explain this independent importance. And I think one can be found if we distinguish the individualism from individuality.

Individualism vs Individuality

In the United States, individualism is a pervasive way of thinking about individuality and hence personhood. From thinkers like Kant and others in the Enlightenment, we got the idea that persons are little atoms, autonomous and independent, interacting with one another largely on the basis of self-interest. We don’t owe other folks much besides staying out of their business.
But in recent decades, some philosophers have pointed out that this vision of individuality is limited to a segment of the population in the prime of life. For significant periods of our lives, we are utterly dependent on others; and even when we are not so dependent, we often have others depending on us. The fully autonomous adult unencumbered by demands from others is much rarer than our intellectual inheritance has led us to believe.
Don’t get me wrong. We owe a great deal to the Enlightenment and individualism. But as with all ideas, we must not overextend individualism in contexts where it loses its utility. Personhood is one such area.
If individualism is an inadequate basis for personhood, we might seek the basis in its opposite, which we might call relationism. Just as being a rational creature puts us in the business of giving and receiving reasons, being a relational creature puts us in the business of forging and improving relations with others.
Even the relatively autonomous are interdependent with others — for instance for income, and for physical and psychological well-being. If respect and space are the way to honor a rational being, then attentiveness, trust, care, and love are the way to honor a relational one.
Conceiving of persons as relational doesn’t cancel out the need to recognize and respect our rational nature, or to give people room for autonomy; instead, it broadens the space in which we think about persons while acknowledging that reason is a big part of who many of us are. If we think of identity as growing from the way we inhabit our intersecting roles and relationships, we can see that the relational conception of persons includes the rational one while preserving the individuality at the heart of personhood.
There is still a great deal to work out in this vision of personhood, but you can probably see already how the idea promises to account for the personhood of children and those with mental disabilities better than the individualistic, reason-based idea will.
Children and the mentally disabled may not be (fully) rational, but they can certainly be fully relational. We owe them recognition in virtue of their individuality. For most strangers most of the time, this is just basic respect and staying out of their business.
But for others, like children and the mentally disabled — like Carla — much more is required. It is required by their personhood.